Thyroid UK
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I have had a blood test and my serum folate is 20.3 ug/L (3.4 - 20.0) "High". I do not know what all this means, but my doctor has not said

I have had a blood test and my serum folate is 20.3 ug/L (3.4 - 20.0) "High". I do not know what this means, but my doctor has not said anything to me about it. Is this serious and should I go back and see my GP and ask him if anything should be done about it? Would be grateful for any help.


19 Replies

It's not that high, it's just at the top of the range.

Can be because:

- you eat lots of folate rich foods

- you didn't fast before the test

- you have a B12 deficiency (folate sometimes builds up un-metabolised if you don't have enough B12, they work together)

- you have problems metabolising folate / methylation cycle defects MTHFR

- SIBO (small intestinal bacterial overgrowth) can cause high folate levels

So really you can't look at a folate result in isolation. You need to look at the FBC for any signs of macrocytosis suggestive of deficiency, you need to look at your B12 test result. Homocysteine would be a good test but not generally offered on the NHS. Most importantly you need to think about symptoms, if any.

H x


Mine is >26.0 ug/L do u know what that means


Thank you very much Hampster1. You mention symptons! What symptons be experiencing, if any?

I did fast before the blood test. I am taking 125 mcg thyroxine and do a lot of dancing (ballroom and latin). I do not sleep well and my weight has never been affected. The only thing being underactive thyroid is my hair. It has become so thin, that i wear wigs. I could go out without the wigs, but honestly my hair looks awful and it has never grown back as it was before I had this underactive thyroid. I am paying a lot of money out for a product called "Nourkrin" and have another six weeks to take it before I have to really see if it has made any difference. I do feel tired a lot but I still dance five times, sometimes six times a week. I get quite a few headaches but then i suffer from sinus problems. I am telling you this because I do not know if they are nothing things or symptons because of this high serum folate. I am not sure what to do next because I am on the NHS and not a private patient.

Thankyou again so much for answering me. It is greatly appreciated.



Have you had B12 tested? It is one of the many things that can cause hairloss, but since you also have top of the range folate I would suspect this. Have a look at this film (the second lady featured):

And here is a full symptom list:

You should also get ferritin tested as low iron is another cause of hairloss. Sinus problems are often linked to fungal infections rather than viral/bacterial:

H x


Thanks Hampster :) that was an eye opener well worth watching, thank Q for sharing it. :) :)


Hi Hampster1 - Thankyou again for answering so quickly. I watched the video and it is amazing what lack of Vit B12 can cause. The GP did test my Vit B12 and it is as follows (which i do not understand) : Serum Vitamin B12

616 ng/L (246 - 911)

thyroid function test - Serum TSH level 3.01 mu/L (0.35 - 5.5)

Serum ferritin - 35.6 ug/L (20 - 300)

There you have my results. I do not understand any of them. My G.P does not seem concerned at all.

I cannot thank you enough for being so kind in answering me and trying to help.

He said I am not diabetic and that my iron was o.k. That is all I can tell you.

I really do not feel ill. If I did I would not be able to dance like i do, but do have lots of symptons like tiredness,

waking up every hour when i go to bed and going to the loo several times in the night. Plus cramp and numbness of feet and sinus headaches. Blimey I have to laugh, I sound as though I am dying. Honestly, I am o.k, and love to dance and will not let anything get me down. My hair has been thin and horrible ever since i was diagnosed about twenty years ago and because i am always dressed up, I have to wear wigs or else I would look and feel awful.

Again, hundreds of thanks and God Bless you for being such a kind person.



Hi - looking back I see you have balance problems - again low B12 is a suspect for that, and is complemented with B complex - (other b vitamins such as thiamine, biotin etc also good for hair growth, and ferritin too) it seems that HypoThyroid sufferers are often low in many vitamins and minerals - EVERYTHING slows down including digestion/absorbtion - so best sort them first so thyroid hormones can have something to use and function better....

I started with Vitamin D (sunshine) but the list goes on..... as Hampster says folate is not in isolation.... J x

1 like

Thankyou for your information Spareribs. I do have trouble with my balance, especially when doing Latin Dancing, like rumba and it is very worrying, but I do take all the vitamins and minerals. I take a Vitamin B Complex 100.

Also my Vit D is o.k according to my blood results. Again thankyou for trying to help me.



Hi Marguerite9,

Because you supplement the Bs your test results won't be accurate, probably explains why you have good folate levels. Also, is that the H&B B-100 complex? That has quite a lot of B6 in it, and too much B6 can actually cause peripheral neuropathy, which reverses when you stop taking it.

I would suggest stopping your B-complex for a couple of weeks, and then switch to something like the H&B Complete B if on a budget:

If not on a budget, Thorne Research are very good and have a few B-complexes to choose from:

Or I take Pure Encapsulations B-Complex Plus:

Shop around because Amazon is not always the cheapest place to buy, I just used their links to show you. I buy my Pure Encapsulations supplements from here (easiest to order by phone):

It's worth remembering you don't have to take a good supplement every day, quality over quantity. As with any supplement, once you've built up levels initially, you should cut back to a maintenance dose.

Having said all that, I feel you need to concentrate on your thyroid and iron levels. Your TSH is still on the high side for someone on replacement hormone, have you had T4 and T3 tested? Your ferritin is on the low side so you would probably benefit from an iron supplement. I don't know too much about it but my ferritin was about 31 and I have been successful in raising it with Spatone to the 50s so far (2x sachets a day with some orange juice or vit C powder). Something like 70 or 80 is where you need to get to. Are you on iron already?

H x


Hi Hampster1 - Thankyou again and again. I am taking note of everything you have told me. Yes I take H & B Mega B-100 Vitamin B-Complex. I will try what you said and stop taking it for two weeks. I will also look the B vitamins up on Amazon. Something else, you said my ferritin was lot. Well here is exactly what it said on my blood test result:

"Serum ferritin" 35.6 ug/L (20 - 300)



Will be filed as : 42T..00 Serum Vitamin B12

A normal ferritin result should not be used to exclude iron deficiency in the presence of liver disease or acute phase reaction. For further information see: http:/ /

the Doctor has said nothing is wrong and nothing to worry about, but after reading everything and having things explained to me by you, I do feel rather confused as to what to do next. Should I make appt. to see him again and if so, what should i say to him? I also forgot to mention to you that I have a bit of trouble with my balance and that is bad for someone like me who loves to dance.

I really do appreciate any help/comments you can give me and do so hope I am not boring you to tears.

Thanks again, Marguerite9


A doctor is unlikely to treat your low ferritin because it is in the normal range. Ditto, they would think nothing of your TSH level. But being in range doesn't really have anything to do with being optimal, particularly if you have thyroid disease.

I would suggest you post another question about your thyroid and iron results and see what people suggest - I'm not hypo myself so can't give you the best links for this.

And don't worry about boring me - that's what I usually do myself, bore on about vitamins instead of thyroid!

And when you reply to someone, use the yellow "reply to this" button, and that person will get an email saying you've responded :-)


Thankyou Hampster1 you have given me lots of things to think about and act upon. I am going to get the iron drink next. It is so nice to have someone listen and try to help when all the doctor says is you are "o.k".

By the way, you did not bore me with the knowledge on the vitamins. I found it all so interesting. Things I never knew about how they build up in the system.

Anyway, I wish you all the best and cannot thank you enough for all your help.



Strictly speaking the B vitamins don't build up in the system, they are water soluble, excess is excreted in urine. It is only B6 that you have to watch daily dose, and folate should be taken in balance with B12.

I just personally think that if you've been feeling good on supplements and then you start to feel bad, it's worth doing a supplement cleanse and then reintroduce at a maintenance level (which would be every day for some people, but less often for others).

Otherwise, we end up popping so many pills that it literally takes over our life. And we lose sight of what we actually need to take, rather than researching, getting tested, and tailoring the supplements to our own needs.


Hampster1 you are a STAR and I am taking note of everything you have told me. In fact just havingt someone trying to help me has made me feel better already. I take Vit C, Vit E 200 i.u, Calcium Magnesium and Zinc, Mega B Complex which the B6 is 100 mg, Cod Liver Oil, Primrose Oil, Odourless Garlic Pearles, Glucosomine Sulphate 1000 mg, Selenium with A, C & E and Co-Enzyme Q-10 30 mg. which I get from H & B. It all works out rather expensive, but I have been taking them for years and feel fine. I have only noticed not feeling 100% is when my doctor lowered my dose of thyroxine from 150 mcg to 125 mcg, but he says this is correct for me. I think he lowered it because a year ago, I had rather a big fright with my husband being ill and I ended up in A & E with my heart going too fast, but they did all the tests on me (everything) and said it was all down to stress and just told me to have de-caf instead of the usual coffee and tea, which I have done and have not had any other fast feelings with my heart since.

Maybe that is why he lowered my thyroxine. My weight is good and stays the same. I am a size 10 in clothes but I think my weight stays good because of all the dancing i do. The thyroid only affected my hair and made it so terribly thin and as I am dressed up a lot, my thin horrible hair spoils everything, hence I wear wigs (again very expensive if you want good ones). Anyway, I am a happy person and love life and people but as i have told you in my previous corespondence have quite a lot of symptons which I do not know if it is because of the thyroid or what. Doctor says there is nothing wrong. I do hope I am not boring you with all this, but you are the only one who seems to talk sense to me and make me think about things. Anyway, i am going to try what you said and I dont blame you if you do not want to answer me any more. I must be getting on your nerves. Again thankyou "STAR".



I think you've answered your own question in there. You were feeling fine until the doc reduced your thyroxine, I'd be back in asking to increase it again. Ultimately your TSH is too high at the moment for someone on thyroxine. And the only thing getting on my nerves is that you're not hitting the "reply to this" button, LOL!!! x


That was a joke by the way!


Honestly Hampster I am hitting that "Reply to this" button and I do not know why it is not showing up properly.

I think I had better make another appt. with the Gp but how do I say to him that I know my TSH is too high as after all he is the doctor and i am the patient.

Thankyou again

Marguerite9 P.S. Sorry for upsetting you.


The fact that you are the patient means that you know more about how you feel than he does, I would be straight with him and say you haven't been feeling good on the reduced dose and you want to go back up again to see if that will do the trick. I think there are some things you can print off - Shaws often posts the links I think?

And I'm not upset you daft thing! Just trying to give you some tips for the forum. I hope I didn't upset you. For "reply to this" you hit the button first, and then type your answer in the new box that comes up underneath. If you want to look at Shaws posts to find the hypo links, click on "members" on the purple bar at the top of the page, search "Shaws" and then you can see their activity (I think).

H x


I am not upset at all but I am new to all this and do not really understand it all but you have helped me and i am extremely grateful.

Marguerite9 x


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